Flu Shot Still Needed Even in 'Mild' Winters

Despite a relatively mild influenza season last year, it remains important to get vaccinated this and every year, flu experts emphasized at a news conference sponsored by the National Foundation for Infectious Diseases.

The 2011-2012 season set a record for the lowest and shortest peak for influenza-like illness since that type of surveillance began, according to Howard Koh, MD, MPH, assistant secretary for health at the U.S. Department of Health and Human Services.

But, "although last flu season was mild, people cannot become complacent this year," he cautioned, pointing to the unpredictability of influenza viruses. "When it comes to flu, we can't look to the past to predict the future. Don't take the risk; get your vaccination."

At the news conference, Koh -- who got his flu shot at the event to illustrate the importance of immunization -- reviewed the CDC's final vaccination coverage rates for last season. Some of the information was also covered in the Sept. 28 issue of Morbidity and Mortality Weekly Report.

Overall, 42% of people ages 6 months and older received a seasonal influenza vaccine, a number similar to the year before. The coverage rate was 52% for those younger than 18, with rates decreasing with age, and 39% for adults, with rates increasing with age.

Koh highlighted vaccination rates in pregnant women and healthcare professionals, two groups that are listed as priorities for coverage by the Advisory Committee on Immunization Practices.

In a panel survey of women who were pregnant at any time from October 2011 to January 2012 -- the usual period for peak influenza activity -- 47% said they had been vaccinated for the 2011-2012 season, which was roughly the same as observed during the previous two seasons.

Coverage was especially high (73.5%) for women who reported receiving both a recommendation for vaccination from a healthcare professional and an offer of vaccination.

Among those who did not receive the vaccine, the most common reasons cited were concerns that the vaccine would cause influenza or would harm the baby and a belief that the vaccine is not effective.

Laura Riley, MD, director of obstetrics and gynecology infectious disease at Massachusetts General Hospital in Boston, noted that an abundance of evidence has accumulated that the influenza vaccine is safe for both mother and baby, with no concerns about increased risks of miscarriage or birth defects.

"The recommendation is that any pregnant woman at any term in pregnancy ... can and should get the influenza vaccine," said Riley, a representative of the American College of Obstetricians and Gynecologists.

For healthcare professionals, an Internet panel survey revealed a 66.9% flu vaccine coverage rate, which is a slight increase from the previous two seasons (63% to 64%). Rates increased with employer requirements, employer promotion of influenza vaccination, or having vaccination offered at no cost on multiple days at the workplace.

By occupation, coverage was highest among physicians (85.6%), followed by nurses (77.9%) and all other healthcare professionals (62.8%).

By workplace, coverage was highest in hospitals (76.9%), followed by physician offices (67.7%) and long-term care facilities (52.4%).

Koh said that the low rate among personnel in long-term care facilities is "particularly worrisome because these professionals typically care for people at higher risk for complications."

William Schaffner, MD, chair of preventive medicine at Vanderbilt University in Nashville, Tenn., said that all healthcare professionals have an obligation to get vaccinated.

"I believe that the immunization of the healthcare provider community writ large is both an ethical and professional responsibility of those healthcare workers," he said, citing both the need to prevent transmission to patients and the need to keep healthcare professionals working when influenza is causing extensive illness in the community.

Daniel Jernigan, MD, MPH, deputy director of the CDC's influenza division, said at the news conference that more than 85 million doses of flu vaccine -- of a projected 135 million total -- have been distributed already.

He said he thinks that should be adequate to meet demand, adding that it is better to get vaccinated before flu activity ramps up.